Flotation process



Patented Oct. 11, 1938 i v 2,132,902

UNITED-STATES PATENT OFFICE FLOTATION PROCESS Samuel Lenher, Wilmington, Del., assignor to E.

I. du Pont de Nemours & Company, Wilmington, Del., a corporation of Delaware No Drawing. Application June 14, 1934, Serial No. 730,551

26 Claims. (Cl. 209-166) This invention relates to aprocess for concenpounds containing in the positively charged surtrating minerals, and more particularly refers face active portion thereof an aliphatic hydroto a froth flotation process whereby a high concarbon radical having from twelve to eighteen centration of minerals which formerly could be carbon atoms.

obtained only with extreme difliculty are sepa- The invention may be more readily understood 5 rated in a rapid and extremely eflicient manner. by a consideration of the following illustrative Heretofore ores have been subjected to froth examples: flotation processes utilizing a soap or analogous Example 1 surface active reagents. These reagents were frequently quite inefficient and resulted in the 1000 a fi i fig i zzz yg 5 53: 22 10 production of a low yield of inferior concens z g To this sus 5 2 was added trates. Because of the inefficiency of such procg on e i (11 i mid 1 d esses the froth flotation of many ores was congram of cetyl num E e z sidered impossible, the reason why the aforesaid m g g 5% i zg a e f processes would float some ores and not others a? i' fi i i f 31:5 1 $3 2 15 being unknown up to the present time, although g g g stmn floccuh'ited several theories had been advanced therefor. o e w e y g y concentrate was obtained consisting of 706 grams The aforesaid flotation agents were, furthermore, unsatisfactory in that largequantities thereof gg gg gg miner the tans amounting to 20 were necessary and the conditions of operation had to be maintained within relatively narrow Example 2 limits. The preceding example was repeated substi- It is an object of the present invention to tuting 0.2 gram of cetyl trimethyl ammonium avoid the previously-described difficulties and the chloride for the cetyl pyridiniuin bromide. Upon numerous disadvantages which directly or indiagitation the ore was immediately and strongly 25 rectly resulted therefrom. A further object is to fl cculat d, A t t was bt i weighutilize as flotation agents compounds which here- 111g 856 grams, the tails amounting to 144 grams. tofore were not known to have flotation properties or to be of any value in flotation processes. Example 3 A still further object is to devise a froth flotation Example 1 was again repeated substituting 30 process wherein ores and minerals which for- 1000 grams of Manavala Kurichi ilmenite for merly could not be concentrated by flotation the feldspar. This ore assayed 90% ilmenite, processes or which were concentrated thereby 7% garnet and 3% miscellaneous minerals. As only with great difiiculty may be readily and a flotation agent 0.4 gram of cetyl pyridinium eificiently separated. A still further object is to bromide was used. The concentrate weighed 651 35 explain the reason why prior art flotation agents grams, and the tails 349 grams.

were unsatisfactory for the flotation of numerous The preceding examples were repeated substiores, and to instruct one in the means of avoidtuting a well known flotation agent, namely soap, ing such difficulties. Additional objects will befor the flotation agents used therein. In each come apparent from a consideration of the folcase an exceedingly poor yield of low quality 40 lowing specification and claims; concentrate was obtained. The use of soap in These objects are attained according to the the flotation of these ores was, therefore, impracprocess of the present invention wherein ores ticable. and minerals in general may be concentrated by It is to be understood that in place of the means of a froth flotation process utilizing comores floated in the aforementioned examples nu- 45 pounds containing a positively charged surface merous other sulfide or non-sulfide or'es might be active ion.' In a more limited'sense the invensubstituted. In particular the flotation of ores tion relates to the froth flotation of non-sulfide which are negatively charged was found to be ores by means of a compound containing a posiexceedingly satisfactory. The determination of l tively charged surface active ion one of the comthe electrical charge of ore particles is readily 50 ponents of which is a hydrocarbon radical havmade by well known methods of electrophoresis, ing at least eight carbon atoms. The preferred such as are described in Holmes,Laboratory Manembodiment of this invention comprises the froth ual of Colloid Chemistry, John Wiley 8: Sons, New flotation of negatively charged non-sulfide min- York city, second edition, 1928, p. 48; and by erals by means of quaternary ammonium com- Ettlsch & Deutsch, Physik. Z. 28, 153 (1927). A 55 -agents.

few representative ores coming within this category and floated according to the present instructions with surprisingly good results are the feldspars as a class; quartz; ilmenite; the pyroxenes, the spinels such as picotite and magnetite; the micas such as biotite and muscovite.

While the invention is particularly adapted for the flotation of negatively charged ores it is to be understood that it is not limited thereto and may frequently be used to float positively charged ores. It may be applied to both sulfide and non-sulfide o1 es. When applied to the former it is in general advisable that the flotation agents described herein be utilized in admixture with the customary flotation agent for sulfide ores. Sulfide flotation agents which maybe used in admixture herewith are, for example, xanthates, mercaptans, thioureas, carbama'tes, etc. In the case of non-sulflde ores the flotation agents described herein may customarily be used without admixing therewith additional flotation However, where the non-sulfide ore to be floated contains a positive charge it is usually advantageous to mix the herein-described flotation agents with soap, soap-like products, watersoluble sulfuric esters of higher normal primary alcohols, sulfonated derivatives of higher fatty acids and higher fatty alcohols, and other flotation agents. The presence of the agents forming the subject matter of the present invention in admixture with other flotation agents results in a more highly selective froth flotation operation, with the consequent production of a higher yield of better quality concentrate than could ordinarily be obtained. The proportion of the individual components in such admixture may vary within wide limits, the agent or agents described herein being used in amounts varying from mere traces to major fractions thereof.

The flotation agents comprised herein are broadly compounds containing a positively charged surface active ion. One familiar with the art in view of the present instructions would have no difliculty in determining the compounds which satisfy these requirements. Among the compounds which come within the aforesaid category a class which has been found to possess particular value is the quaternary ammonium compounds. These compounds are especially advantageous when the positively charged ion thereof contains a' hydrocarbon radical having at least eight and preferably from twelve to eighteen carbon atoms.

In this connection, an aliphatic hydrocarbon radical has been found to be especially advantageous. The negatively charged ion of said compound should preferably possess little or no surface activity, although as long as the surface activity of the positively charged ion is appreciably greater than that of the negatively charged ion the compound will func ion satisfactorily. Halogen atoms have been ound to be particularly suited for use as the negatively charged ion. These atoms possess negligible surface activity and consequently permit the positively charged ion to function with maximum selectivity.

In addition to the previously mentioned hydrocarbon radical, the positively charged portion of the flotation agent may advisably contain one or more of the commonly known substituents. For example, aliphatic and/or aromatic radicals which may be further substituted by alkyl, alkoxy, nitro, amino, halogen, carboxy, sulfonic acid, benzoylamino, diphenylamine, etc.

groups. The compound may contain more than one hydrocarbon group of high molecular weight and such group or groups may be further substituted as in the case of the remaining portion of the molecule. Compounds which illustrate such instructions but are not intended as a limitation thereon are:

Cetyl trimethyl ammonium bromide or chloride Lauryl trimethyl ammonium chloride or iodide Cetyl pyridinium bromide Dimethyl benzyl phenyl ammonium chloride sul-' fonated in benzyl ring Beta diethyl amino ethyl oleyl amide acetate Beta diethyl amino ethyl oleyl amide hydrochloride Trimethyl ammonium methyl sulfate or amino oleyl ethylene diamine Quaternary ammonium compounds containing at Octadecyl pyridinium chloride Octadecyl pyridinium iodide Octadecyl alpha picolinium bromide Octadecyl quinolinium bromide Dodecyl pyridinium bromide Heptadecylamine hydrochloride Hexadecylamine hydrochloride Dodecylamine hydrochloride.

In the past many ores were floated only with great difficulty or were found to be impossible to float because it was never before appreciated that the compounds selected for flotation should be chosen in accordance with the electrical charge present on the ore. For instance, soapv was a customary flotation agent for all non-sulfide ores. The surface active portion of soap contains a negative charge. Consequently, where the ore to be floated also contained a negative charge soap was quite inefiicient as a flotation agent. The

present invention discloses a means of overcoming this difficulty, and permits the particular characteristic of the ore which defeated its flotation in the past to befused to advantage.

The flotation agents described herein for the first time, while being particularly adapted to the flotation of negatively charged ore are, as previously mentioned, not restricted thereto. These compounds have in addition to their positive charge an extremely high surface activity. As a result thereof, even when the ore to be floated is positively charged this surface activity of the flotation agent will produce a satisfactory yield of good quality concentrate. The agents described herein contain positively charged particles, ions or micelles. As a result of this phenomenon the surface active particles speedily form agglomerates or flocks on the surface of the ore to be floated and aid to a surprising extent in raising said ore to the surface. In addition to bringing the desired ore to the surface the present invention may be so modified that the desired mineral remains submerged and the undesired components of the ore are brought to the surface and separated therefrom.

The present invention permits the use of an exceedingly large number of compounds in the froth flotation of ore. These compounds werev heretofore unknown to haveflotation properties. As a result of this invention ores which formerly could not'be subjected to froth flotation or when so subjected were quite unsatisfactory may now be treated by froth flotation processes with surprisingly good results. The operation is speedy and need not be maintained within narrow limits.

As many apparently widely different embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims.

I claim:

1. A process for the froth flotation of negatively charged non-sulfide ores which comprises frothing an aqueous suspension of said ores in the presence of an organic compound, the surface active portion of which is a positive ion.

2. The process of claim 1 wherein the positively charged surface active ion contains a hydrocarbon radical having at least eight carbon atoms.

3. A process for the froth flotation of negatively charged minerals which comprises agitating a liquid suspension of said minerals in the presence of a compound containing a positively charged surface active ion, said ion containing an aliphatic hydrocarbon radical having from eight to eighteen carbon atoms.

4. A process for the froth flotation of negatively charged minerals which comprises agitating an aqueous suspension of ore containing said minerals in the presence of a quaternary ammonium compound having a positively charged surface active ion.

5. A process for the froth flotation of negatively charged minerals which comprises agitating an aqueous suspension of ore containing said minerals in the presence of an ammonium compound having the following general formula:

wherein R represents an aliphatic hydrocarbon radical having from 8 to 18 carbon atoms, R2 represents hydrogen or hydrocarbon radicals or both hydrogen and hydrocarbon radicals, having a total valence of 3, and X represents a negatively charged group possessing negligible surface active properties when in solution.

6. The process of claim 5 wherein X represents -a halogen atom.

7. The process of claim 5 wherein X represents a chlorine, bromine or iodine atom.

8. A process for the froth flotation of nega-' tively charged non-sulfide ores which comprises agitating and aerating an aqueous suspension of said ore in the presence of a nitrogen-containing organic flotation agent, the surface active portion of which is positively charged.

9. A process for the froth flotation of negatively charged non-sulfide ores which comprises agitating and aerating an aqueous suspension of said ore in the presence of a nitrogen-containing organic compound having a hydrocarbon radical of at least 8 carbon atoms, the surface active portion of which is positivelyqcharged.

10. A process for the froth flotation of negatively charged ores which comprises agitating and aerating an aqueous suspension of said ores in the presence of an ammonium compound hav;

both hydrogen and hydrocarbon radicals, having a total valence of 3, and X represents chlorine or bromine.

11. A process for the froth flotation of negatively charged ores which comprises agitating and aerating an aqueous suspension of said ores in the presence of an ammonium compound having the general formula:

wherein R1 represents an aliphatic hydrocarbon radical having from 8 to 18 carbon atoms, R2, R3 and R4 represent hydrogen atoms, and X represents a halogen atom.

12. A process as set forth in claim 11 wherein the ore treated is quartz.

13. A process for the froth flotation of negatively charged ores which comprises agitating and aerating an aqueous suspension of said ores in the presence of dodecylamine hydrochloride.

14. A process as set forth in claim 13 wherein the ore treated is quartz.

15. A process for the froth flotation of negatively charged ores which comprises agitating and aerating an aqueous suspension of said ores in the presence of an ammonium compound hav ing the following general formula:

wherein R1 represents an aliphatic hydrocarbon radical having from twelve to eighteen carbon atoms, R2, R3 and R4 represent hydrogen atoms, and X represents chlorine.

16. A process for the froth flotation of negatively charged ores which comprises agitating and aerating an aqueous suspension of said ores in the presence of a quaternary ammonium compound having the following general formula:

wherein R1 represents an aliphatic hydrocarbon radical having from 8 to 18 carbon atoms, R2, R3 and R4 represent hydrocarbon groups, and X represents a halogen atom.

17. A process as set forth in claim 16 wherein the ore treated is a mica.

18. A process for the froth flotation of negatively charged ores which comprises agitating and aerating an aqueous suspension of said ores in the presence of cetyl trimethyl ammonium bromide.

19. A process as set forth in claim 18 wherein the ore treated is muscovite.

20. A process for the froth flotation of negatively charged ores which comprises agitating and aerating an aqueous suspension of said ores 4 amae oa atoms.

22. A process for the froth flotation of negatively charged ores which comprises agitating and aerating an aqueous suspension ofsaid ores in the presence of a quaternary ammonium compound having the following general formula:

wherein R1 represents an aliphatic hydrocarbon radical having from 8 to 18 carbon atoms, and

- X represents a halogen atom.

23. A process as set forth in claim 22 wherein the ore treated is a feldspar.

24. A process for the froth flotation of negatively charged ores which comprises agitating and aerating an aqueous suspension of said ores in the prmence of cetyl pyridinium bromide.

25. A process as set forth in claim 24 wherein the ore treated is a feldspar.

26. A process for the froth flotation of negatively charged ores which comprises agitating and aerating an aqueous suspension of said ores in the presence or. a quaternary ammonium compound having the following general formula:

wherein R1 represents an aliphatic hydrocarbon radical having from 12 to 18 carbon atoms, and X represents bromine.

SAMUEL LENHER. 

